Characterization of photosynthetic epilithic biomass on the river bed of the Upper Clark Fork River (Montana, USA) during the algal growing seasons of 2017 and 2018

These data were collected to support monitoring of the Upper Clark Fork River restoration, and data collection was funded by the US NSF Long Term Research in Environmental Biology (LTREB) program and the US NSF EPSCoR funded Montana Consortium for Research on Environmental Water Systems. The LTREB monitoring project consists of monthly or bi-weekly water quality monitoring across a 200-km restoration gradient contaminated by historic mining practices to monitor inorganic phosphorus and nitrogen concentrations, biotic standing stocks, and heavy metal contamination. The original analytical intent for these data was to assess the response of the river algal community to the floodplain restoration. Data characterize epilithic biomass on the river bed including measurements of benthic standing stocks and abundance of pigments associated with primary producers. Metrics of characterization include areal density of chlorophyll a, areal density of phaeophytin, the ratio of carotenoid to chlorophyll absorbance, percent organic matter, areal density of organic matter, and category of biomass composition (filamentous algae vs. other epilithon). Samples were obtained from collecting and scrubbing five rocks at any given site. Biomass estimates were obtained from area corrected Ash Free Dry Mass. Pigment concentrations were obtained through the use of extraction in acetone followed by spectroscopy. Data are from the 2017 and 2018 algal growing seasons. Data were collected on the Upper Clark Fork River (USGS HUC 17010201) at project sites distributed along the river from the vicinity of Anaconda to Missoula, Montana, USA.

本数据集采集的目的是支撑克拉克弗克河上游（Upper Clark Fork River）修复工程的监测工作，数据采集经费由美国国家科学基金会（US NSF）长期环境生物学研究（Long Term Research in Environmental Biology, LTREB）项目，以及美国国家科学基金会EPSCoR资助的蒙大拿州环境水系统研究联盟（Montana Consortium for Research on Environmental Water Systems）提供。LTREB监测项目覆盖受历史采矿活动污染的200公里修复梯度带，按月度或双周频次开展水质监测，以追踪无机磷、氮浓度、生物现存量与重金属污染状况。本数据集最初的分析目标为评估河流藻类群落对河漫滩修复工程的响应效果。数据集表征河床石面着生生物量（epilithic biomass），涵盖底栖生物现存量以及与初级生产者相关的色素丰度测定内容。其表征指标包括叶绿素a（chlorophyll a）面密度、脱镁叶绿素（phaeophytin）面密度、类胡萝卜素与叶绿素吸光度比值、有机质占比、有机质面密度，以及生物群落组成类别（丝状藻类与其他石面底栖生物（epilithon））。采样方式为在每个指定采样点采集并刷洗五块岩石；生物量估算采用经面积校正的无灰干重法（Ash Free Dry Mass）完成；色素浓度则通过丙酮萃取后结合光谱分析法测定。本数据集涵盖2017年与2018年藻类生长季的监测数据，采样点位分布于美国蒙大拿州从阿纳康达周边至米苏拉的克拉克弗克河上游河段（美国地质调查局水文单元代码：USGS HUC 17010201）。